CoArray Fortran Framework of Efficient Interfaces to Network Environments
Caffeine is a parallel runtime library that aims to support Fortran compilers with a programming-model-agnostic application interface to various communication libraries. Current work is on supporting the Parallel Runtime Interface for Fortran (PRIF) with the GASNet-EX exascale-ready networking middleware. Future plans include support for an alternative Message Passing Interface (MPI) back end.
The install.sh script uses the following packages:
- Fortran and C compilers
- GASNet-EX exascale networking middleware
- Fortran package manager
fpm - pkg-config
- realpath
- make
The script will invoke these if present in a user's PATH.
If not present, the script will ask permission to use Homebrew to install the relevant package.
Caffeine leverages the following non-parallel features of Fortran to simplify the writing of a portable, compact runtime-library that supports Fortran's parallel features:
| Feature | Introduced in |
|---|---|
The iso_c_binding module |
Fortran 2003 |
The contiguous attribute |
Fortran 2008 |
| Submodule support [1] | Fortran 2008 |
do concurrent [2] |
Fortran 2008 |
The ISO_Fortran_binding.h C header file |
Fortran 2018 |
Assumed-type dummy arguments: type(*) |
Fortran 2018 |
Assumed-rank dummy arguments: array(..) |
Fortran 2018 |
[1] This feature simplifies development but is not essential to the package
[2] This feature is used to support only co_reduce and might become optional in a future release.
git clone https://github.com/BerkeleyLab/caffeine.git
cd caffeine
./install.sh
export GASNET_PSHM_NODES=8
FC=<Fortran-compiler-path> CC=<C-compiler-path> CXX=<C -compiler-path> ./build/run-fpm.sh run --example hello
./build/run-fpm.sh test
For details on the PRIF features that are implemented, please see the Implementation Status doc.
Damian Rouson, Dan Bonachea.
"Caffeine: CoArray Fortran Framework of Efficient Interfaces to Network Environments",
Proceedings of the Eighth Annual Workshop on the LLVM Compiler Infrastructure in HPC (LLVM-HPC2022), November 2022.
Paper: https://doi.org/10.25344/S4459B
Talk Slides
Dan Bonachea, Katherine Rasmussen, Brad Richardson, Damian Rouson.
"Parallel Runtime Interface for Fortran (PRIF) Specification, Revision 0.4",
Lawrence Berkeley National Laboratory Technical Report (LBNL-2001604), July 2024.
https://doi.org/10.25344/S4WG64
One of our continuous integration (CI) scripts generates up-to-date Caffeine documentation using ford. The CI script also deploys the generated documentation to the our GitHub Pages site. Alternatively, generate HTML documentation locally using ford as follows:
ford doc-generator.md
Open doc/html/index.html in a web browser.
The Computer Languages and Systems Software (CLaSS) Group at Berkeley Lab has developed Caffeine development on funding from the Exascale Computing Project (ECP) and the Stewardship for Programming Systems and Tools (S4PST) project.
See LICENSE.txt for usage terms and conditions.